Well, I played game and came back to main menu. Then when I again selected play button it didn't work.
the play button is disabled untill its received all the http requests from lootlocker which is there to fix some errors that would happen internally, so just give it like half a minute and the button should work fine, same thing goes for setting different songs, which you can more easily tell if its ready when the scores have all loaded/overwritten
Its my bad on the implementation, which should be fixed after jam